Diagnosis of Intermittent Hesitation, Skip, or Miss 2000 Trans Am- PART 1
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- čas přidán 13. 08. 2013
- Diagnosis of a very intermittent "hiccup" when car first rolls off from a stop- no check engine light to help with direction. Many thanks to my first subscribers Dave (Spelunkerd) and 12VGS for assistance with selecting equipment for improvement of A/V quality. I didn't go the HD route, but I think you'll notice a definite improvement in production quality.
- Auta a dopravní prostředky
@12VGS-Thanks for the comment and glad you appreciate the video quality improvement. The reason to not do fuel cleaner is because that never does anything and is a "parts changer approach"- clearly fuel cleaner would never have reconnected my CIS. As for "free" checks like cleaning MAF- there's no reason to- the fuel trims clearly indicate it is not a dirty MAF nor a vacuum leak. There is no reason to check for a vacuum leak that cannot possibly exist nor clean a MAF that is not dirty.
Thank you for your videos! Had intermittent hesitation on my 95 Olds Station Wagon. Replaced many things before watching your vids to include: wires, plugs, ignition coils, and PCV or something like that. Mechanic cleaned throttle body and put a gas additive in. Still hesitated. Brought it back he put a new fuel filter on and more gas treatment. Still hesitated. I Brought it back again. When I went to pick up the car he told me he was clueless and told me to take it to a dealer. Frustrated yet more educated after watching your videos I told him I was no mechanic but insisted he install a new TPS. If this did not work I was going to buy a multimeter and check my MAF and MAP sensors myself. Particularly my MAF because I learned on your video (if I understood your correctly) if you have both a MAF and MAP the MAP does not really affect the 14.7 : 1 ratio. In any event the hesitation ceased after the new TPS was installed. However I was stalling at stop signs etc. I unplugged the ECM fuse, plugged it back in, let it run 10 mins. Shut it off and turned it back on for 10 mins for a computer relearn. All is well! Car is running perfect! Thank you so much!
i take so many notes, best channel ever. thank you for everything.
Lol thats exactly how I learned. I have volumes and volumes of notes that I still refer back to!
@@SchrodingersBox what was the problem??
lots of funnies in this upload Matt. very entertaining, and enlightening!. Great stuff.
I didn't know this was 9 months old or that part 2 was done! I need to watch it now :)
ScannerDanner 😂 me too sir
Ahh, going over your old videos here, I see where you got the ignition intro to your videos. Cool (especially with those shades, haha😎)
This man is a great mechanic 👍
Good stuff, as always!
Shro thanks for all of your great videos.
i really like your videos man.. appreciate your work. greetings from germany
+chr1zy0 Ah Germany! Hey do me a favor (and yourself)- send me a PM with your email address and a reminder you are from Germany.
+Schrodingers Box that sense of humor...
I love the new video and audio, dramatically better.
This is a great case, and I'll have to spend a little time thinking about the situation.
I'm wondering what fuel pressure would be at the moment you suddenly went lean after a rev of the engine. If the problem is only occasional and intermittent, it may not happen often enough to show up as a change in LTFT. A fuel pump may be able to produce pressure at idle, but under load it may not deliver full volume....
Later, ha ha.
Thanks you so much for sharing your knowledge, You don't know how much I hate to go buy a part just to find out that it didn't fix the problem and now I have to go buy another part.
I have a bmw z4 3.0si L6, and it often cuts power if I try to launch it from standstill in the first gear only. It happens less often with dynamic traction control on. It did that more often when it was on fuel reserve. I though it could be that the fuel pump wouldn't suck the fuel if you accelerate too hard but not sure about that. I don't have any fault codes, stft and ltft are within 4%
your time and effort much appreciated keep up ya good work and if you get some time introduction to using a scope budget buying cheers
Thankyou so much sir.
video sound excellent. thank you
Hi Schrodingers Box, greetings from Europe !
I have a tough one too for you. Now I know this may not be a car you will ever see in your area but it still is a 4 pot NA engine.
I'm talking about a 1.4 liter NA Peugeot, 1999 with an issue that I haven't been able to solve since last year. The engine doesn't have a MAF, it is the old type with only a MAP, TPS, IAC, IAT in the throttle body. Here are the symptoms:
When engine is cold, in open-loop, turning on AC, or electrical loads like headlights + defrosting or even operating window motors instantly kills the engine or almost kills it. Now, this happens ONLY at cold start, ONLY one TIME ! For example, I start the engine, push the AC button before the engine goes in closed-loop, the engine just stalls, I restart the engine, the AC compressor engages but the engine doesn't die. It seems like the IAC doesn't react quickly enough to compesate the load, but after one "stalling" it does, I don't know if the ECU is forced into closed-loop mode after stalling but everything is absolutely perfect in closed-loop after engine is warmed up. I have no DTCs, I have a new IAC, battery, cleaned the throttle-body twice. I even bought the Peugeot\Citroen scantool but everything seems fine. The dealer has no ideea about this also.
I'm going to make a video and upload it in the morning.
Roberto Cristian no reply because he doesn't know , he makes videos on what he just learned from youtube, ask him a real question and you don't hear from him .
I try to find out as much info about these Pontiacs i have a 97 but the whole ecu turning is really? I grew up with older cars tuning with distributors and carbs and techs and you seem to explane things more in depth like it though.
The MAP sensor is a potentiometer and could have a dead spot as well.
What kind of scanner do you recommend to check the STFT and LTFT graph affordable less or at least less than 500 dls
I was thinking that a forgotten rag/cloth, left in the intake to stop anything falling in, could cause this..
Slowing the car down occasionally as it is slowly chewed up by the valves
Ive seen it twice. it is a stupid problem to have,
But it happens..
i HAVE intermittent stalling too, on my 2008 ford explorer(EXPODER) sport trac. started after the enging was replaced, with a used one. ALL Ford Exploders have catastrophic engine failure around 100,000 miles.
All ford explorers have catastrophic engine failure around 100,000 miles? What evidence do you base this on exactly- what is your source for this statistic exactly?
what was the reading for all 8 injectors 34 I want to watch more.But I'm curious to why it only happens when I'm first gear.And what I that mods are done to the trans am love the cganil though.
7:50 Immediately brought a big smile to my face :D
Love that roar!
DerPapierfliegernarr LOL
Hey there big fan of all your work in your apparently unique attitude toward diagnostic problems I have a problem with a 2005 Nissan Xterra it's a crankshaft position sensor code is there anything else that can make throw this phone decides the crankshaft position sensor? Bad cats maybe?
Lots of things can. So always start with the basics: determine the algorithm (hall effect or inductive) and verify all inputs and outputs are present and coordinate with the camshaft sensor.
@@SchrodingersBox yes I am slowly doing it the right way now I think by doing what you say, I'm just figuring this out this is my third month believe it or not on this project lol
What scan tool are your using? Thanks for the very informative videos.
Autoenginuity
good video
Nice ride, wonder what the problem was.
you were talking about shrader valves not all GM fuel injection systems have them, much older TBI setups dont have the shrader valve. i owned several TBI cars, they are solid and simple but testing fuel pressure isnt easy
Video quality is lot better now! I can't give you hard time any more :-)
I understand that you do not want to take parts change approach. However, why not
put fuel system cleaner, clean the MAF, listen for the vacuum leaks, look for the fuel trims etc as a starting point?
What scanner or program do you have for doing that injector pulse test?
Very cool car, my friend just bought a similar car a ‘96 z28 convertible, not a manual trans like yours, but very cool and fast though. 👍
what if the hiccups or hesitation happened only if the car is already running for several minutes (i.e. 20-30mins) or several miles, and the gear is shifting and downshifting @ 2nd and 3rd gear. I have 05 Chevy Equinox LT, 3.4L V6 5-speed A/T.
What data do you have?
how do you record all the data from the diagnosis tool?
do you ride around with a laptop?
Yes
i have experienced similar results but never found the culprit.
Hi Schrodingers Box, recently subscribed to your channel. u got great diagnosis videos. would really appreciate if you could make video on how to diagnose no start condition in detail with every possible reason. recently had a problem with a car. this guy i know changed the timing belt on his car and car doesnt start. timings were okay. getting fuel and spark. was getting very low compression about 50 in all cylinders. wanted to check crank angle sensor and cam angle. but didnt know how to. anyways, if you could make a video on no start condition would really help beginners like us. thank you.
I know this was 5 months ago, but if he's getting only 50 psi in all cylinders, then the timing belt was not installed properly. OR there could be a big intake restriction like an IAC stuck closed.
The only reason I know this is from watching scannerdanner.
Hi Matt, I have made a few comments in a few of your videos. You may answer my questions there or here, but I will ask here since I am basically chasing a similar issue to this. Where it was fairly intermittent, it is now repeatedly occurring and doing so to a point of making the truck not driveable up to speed or climbing hills etc. The main issue is sputtering, bucking and seeming like starving for fuel when increasing throttle to accelerate up hills or enterign highways, but also it is felt when I was able to be at highway cruising speeds and would still feel it. I guess my questions should go to what scan tool/test equipment will be best to acquire to diagnose a 1994 Ford F150 with OBD1, Map and Maf, etc.?
I obviously am not interested in the cost of being a parts replacer without being able to test the actual causes. As mentioned in a previous comment elsewhere, I am doing a jumper wire code checks with KOEO and KOER. I also have a Vac tool, a DVOM to check voltages, Ohms, Compression testers and a few others I have access to like a fuel pressure tester etc. So, I am asking how I can get the right scan tool for OBD1, so I can make my way through diagnosis without wasting money on a tool that won't work. Thanks
A 94 is OBD-1. I always check those manually just using a simple DVOM actually. Otherwise I'd need different scantools for different models.
Thanks Matt. I got a laugh at what my friend said when we were discussing various processes that are needed to get the OBD1 codes. We mentioned the KOER and turning steering wheel, stepping on brake, Quick throttle rev, and Overdrive on/off button. He said he is surprised they don't require the tester to jump up and down on one foot while eating a bowl of Cereal to get the OBD1 codes.
Hi Matt, I have watched quite a few of your vids and have done lots of reading through my manual and searching the web to read a number of detailed testing resources pertaining to my fault codes I came up with after buying an Innova OBD1 Scan tool. I am writing to possibly get a bit more of a direction from you on a more concise and logical diagnosis procedure based on your experience and my particular truck and tools I have on hand. I will see if I can make my situation as detailed and yet explain what I have done up till now.
First, I only have my OBD1 Code reader, a fuel pressure gauge, DVOM, Test Light, Compression Tester, Spark tester, Timing Light, Mity Vac Pressure and Vac tool, and likely a few more DIY test type tools.
2nd, My truck is the 1994 Ford F150 Automatic with OD, and 5.0 Vin N style with a Inner Fender mounted TFI and a CCD Closed Bowl type distributor with the PIP( Hall Sensor) whatever the real name of this Pickup coil thing is. No MAP sensor, only MAF. I was getting an intermittent miss sputter jerky sensation mostly at highway speeds, and a preignition type sound plus this sputtering feeling when accelerating up to speeds such as getting up to highway speeds and going up hills or towing a 16 foot with or without a car on it. Now it is all the time at this speed, but not at idle. I was not getting a Check engine, but now I am, plus the truck will not stay running upon start up unless I give it gas till it smooths out.
with my OBD1 code reader for Ford, I got the 332 insufficient EGR flow detected, 211 PIP circuit fault, and 172 Hego Shows always runs lean codes. Based on your vids, and my written test procedures, and as many voltage and resistance readings I have taken so far, I have ruled out the IAC, TPS, and pretty sure MAF ( I will have to recheck this) I also was beginning to check specs for the ICM for the PIP and Spout Specs but began to get rained on so I quit. Other items I have not checked yet are Spark Plugs, SPark PLug Wires, ECT, IAT, Coil, and Fuel Pressures. I have to leave it at this point so far but will return to see any replies and to update you on anything else I have discovered. I also found a TSB on possible frayed or shorting wires in the harness over by the TFI and EEC of which the condition is said to cause these symptoms. Thanks for any advice and orderly simplification of testing I can do with my DVOM. Sincerely Mark
Hey Matt, quick question- The DC Sport 4-1 exhaust header that I installed on my Civic 1.7 VTEC cracked on one of the tubes. No engine light codes except P0141 bad post cat O2 sensor heater. The car seems to be slightly low on torque and a little less responsive at low RPMs but runs great otherwise. Gas mileage also seems a little low. Could the cracked header affect engine performance and fuel efficiency or just be louder? Thank you. I love your videos.
If the LTFT is compensating there will be no performance loss however you would be having fuel economy reduced.
if you are unable to reach stoic then yes the engine is running lean causing you to have even less than horsepower than that little 1.7L car already has.
Schrodingers Box Thank you for responding so quickly. How would an exhaust leak cause a lean condition? If anything, wouldn't it make it run rich from air entering the exhaust before the oxygen sensor making it read lean and adding fuel?
Avery Alexander Yes you are correct. An exhaust leak causes what I call a "false lean". The O2 sensor reads lean but because it from exhaust leak and not combustion imbalance the engine itself runs rich.
So yes the engine is not actually "running lean". To be accurate it is "responding lean but running rich".
Schrodingers Box Thank you for your help. Will running it rich cause cylinder wash or fuel in oil?
Avery Alexander Yes, definitely. Running rich also will ruin the cats quickly
‘Nobody puts baby on the coder’ ouch!!!! Made me giggle though 👍
Speaking of coders, how do I get my hands on something like Autotap or what do you recommend to us DIY 2%ers in 2019 please 😁
I recommend Auto Enginuity. By far my favorite.
Damaged ring gear or faulty speed sensor?
That's the way my Dads Audi is acting,he thinks its the turbo,sometimes it has a lull in power and other times its fine,greetings from Eire.
Maybe not on your car - but what about a "miss" 1st to 2nd gear in Transmission, or is it always a Engine problem?
Good question- Not really in this case because an automatic transmission slip would have shown the RPM's to spike and we don't see that- we see the opposite if anything indicating this is not a transmission slip.
You said you used the $400 scan tool, what scan tool is it?
Todd
Annapolis, MD
CRP touch pro.
I love ur you tube
I don't like 62 counts on the IAC at idle but not knowing run time and engine temp I cannot be sure. Typical hot engine, no loads, in park IAC count on a GM is around 30. This is suggesting a dirty throttle body which can give you your symptoms. Although typically you would also have an intermittent stall.
Yeah I agree except that I believe the IAC reading may be the result of the many bolt-on mods, aftermarket intake, etc that I did many years before I got into really understanding engine performance or even got a scan tool. All I know is the IAC has always read that high and as far as I'm concerned it's the baseline on this car given the mods it has.
Schrodingers Box
makes sense for sure. thanks!
Did you ever make the Part Two on this ? I can't seem to find it yet ?
Tim Moss Yes I did.. Diagnosis of Intermittent Hesitation, Skip, or Miss 2000 Trans Am- PART 2
Just seen it ! Thanks for the prompt reply. Tim :)
You sir would be fun to party with , sorta remind me of Will Hunting lol ... how ya like dem apples! :)
Hi,I need your latest video, thanks
Im not a fan of that body style but they do perform very nicely. Id like to put that running gear in a 3rd gen Camaro Z28.
A 3rd gen Camaro? with a 305 at hardly 200HP vs the 4th gens with 335 out of the box (mine is supercharged running 710HP).
Yeah I’ll pass on the 3rd gen. Literally.
@@SchrodingersBox The third gen just needs a LS swap. Handles great looks amazing. Of course you would blow the doors off off it in stock forum. 700 +hp is awesome.
Is it possible to not allow a car to go into closed loop?
Absolutely. many ways to do that- but the question is, why would anyone ever want to do that?
Also I'm not a fan of watching fuel trim during rapid throttle changes. Usually a system drops into open loop during these conditions which makes watching fuel trim irrelevant. Though you did show a very positive spike during the surge.
You know, I have found that different cars seem to have different responses on fuel trim during throttle changes and I have always been convinced it's dependent on the communication speeds between my scantool (Which is like only $400) and the CPU. In instances like this one I always limit the PIDS to get the fastest possible refresh rate and it happens to be on this car it is almost like connecting with a scope. On other cars I would probably never have "caught" the fuel trim changes. There's a lot of things I don't understand on how and why The data showed as it did, all I know is it gave me the direction needed to ultimately find that loose switch. I count on guys like you, Danner, to cover those how and why topics lol!!!
I am not, I am in Denver. Paul (Scannerdanner) is in Pittsburgh, the accent gives him away lol
Schrodingers Box
that's funny. It's that obvious huh?
*****
haha I don't say yinz. I hate that!
*****
haha no, I'm just signed in under my other channel right now. Sorry about that.
vibration on injector wire from engine. before i finish video. yes no?
No lol.
Last time i had an intermittent hiccup in 1st or even 2nd gear that went undiagnosed, it turned out to be the camshaft pos sensor harness.
man I probably have 3 or 4 videos with exactly that.
@@SchrodingersBox my 99 V6 mustang cam pos sensor harness didnt match what the wiring diagram colors in the chilton book, but it did match the GT harness. Odd, i thought. After i spliced a ground wire into the signal wire, it fixed my timing issue immediately. :)
thing of beauty hell yes that car is god. i love my 1996 LT1 Z28 its not LS1 but its not far off either. still an awesome car and i too am partial to it, its my car lol
The problem is hair line cracks in spark plugs you need to use double platinum plugs instead of iridium been there done that problem solved.
Why would you say that when clearly even a novice can tell this is not an ignition problem from the data???? What part of the data are you looking at which even remotely indicates an ignition problem???
Hook your exaust up to go outside black out the window if you have one in your garage start the car let it reach ideal operating temp shut everything up complete darkness get your flashlight find your way under the hood all lights out check for escaping sparks anywhere and everywhere this will cost you nothing but a little time
Damn that car sounds good as fuck at start up
sounds even better now with the supercharged LS7 swap!
@@SchrodingersBox I bet it does lol.
Part II here:
czcams.com/video/BTKGlM5B3W8/video.html
trans am!!! I have two trans am 96-97
so this is where the sound of intro came from😅
Exactly!!!!
air fuil mixture
+jeffrey james yes einstein we all saw the LTFT/STFT plot. WHY is it fuel mixture??
Sweep your TPS with your scope. The glitch MAY NOT be caught with a scan tool!
This video predated my scope acquisition otherwise I would have done that!
I figured that out after viewing more of your videos. I am glad you picked up a scope... great price by the way!
throttle position sensor
Why would you say that? What data indicates this?
@@SchrodingersBox many people can guess part names but few can troubleshoot using Live Data Pids to corner the problem 👍🏻
people would rather complain about computers than learn to use Obd2 data 😂
Good thing we didn't get up to 88 mph
maybe the muffler bearing ?
Poochie43124312 must not have changed the muffler bearing fluid I guess!!
yeah its always something.
Schrodingers Box Doubt it, it's probably the blinker fluid tbh, the muffler bearing should be fine, that is of course unless your oil pressure stays at around 40 PSI. Only then will you have a problem, who knows!
1:00 found the problem. the driver, 20 mph in first gear. are you nuts?
Lol- you haven't seen my car apparently.... I gtenerally don't shift to second until 25mph!
My current rental tells me to go to 3rd gear at 25mph whahaa
25mph at third gear. Talk about a car that would need a clean out.
Opel Corsa 1.3 diesel rental...
Well diesel, that's a complete different animal compared to a Chevy LS engine. The LS could probably wait till 60mph before shifting for third
Honda civic haha! Very good joke
Sticky injector
Based on what evidence?
😹
Schrodinger is Dead ..!!!
Drawing board I thought it was white board of knowledge
vacuum lines,,hoses,,,,gas pump lines filter etc electric
Why would you say vacuum lines, hoses and gas pump line given the fuel trim numbers shown? That makes no sense to me.
Honda civic haha! Very good joke